Competition, facilitation and environmental severity shape the relationship between local and regional species richness in plant communities

Ecography, Год журнала: 2014, Номер 38(4), С. 335 - 345

Опубликована: Окт. 20, 2014

Understanding the relative contribution of local and regional processes to species richness is an important ecological question a subject controversy between macroecologists community ecologists. We test hypothesis that dependent on environmental conditions effect should be highest in communities from intermediate positions along severity gradients due importance facilitation. used recently developed log‐ratio method analyze relationship (LSR) (RSR) for 13 plant 4 habitat types France (coastal sand dunes, oceanic heathlands, alpine grasslands, lowland calcareous grasslands). Each type was split 3–4 using multivariate analyses identify stress, disturbance, competition, facilitation functioning within communities. found LSR/RSR highly with saturated occurring more frequently than unsaturated highlighting drivers richness. argued competition most likely main source saturation whilst contributed enhancing pool all types. However, might stronger disturbed stressed systems because curves were only observed former conditions. In extreme disturbance LSR controlled by intensity disturbance. This not stress Our study provides support emerging balance theory both are nature their depending Additionally, this synthesis strongly suggests contributes process – influence

Язык: Английский

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Facilitation among plants as an insurance policy for diversity in Alpine communities

Functional Ecology, Год журнала: 2015, Номер 30(1), С. 52 - 59

Опубликована: Авг. 12, 2015

Summary Positive interactions have started to gain a place as important drivers of community structure and biological diversity. Defined non‐trophic interspecific that increase the average individual fitness one species, by definition, presence plant species enhances chances another co‐occur in same place, indicating positive may determine However, this has been poorly explored. The majority studies addressing community‐level consequences facilitation compared diversity assemblages growing within nurses vs. those outside them, reporting contrasting results among them. Nonetheless, their alternative microhabitats (open areas nurses) are part community. Thus, if allow for persistence otherwise would be excluded from community, net at entire level will generated even though nurse plants contained fewer than open areas. Here, we conducted bibliographic search using ISI Web Knowledge data base reviewed literature on alpine communities where assessments were available. In most cases substantially increased richness level, despite fact some cases, they lower numbers Nurse enhanced more systems with impoverished local diversity, suggesting facilitative habitats act an insurance policy sustains under very harsh conditions.

Язык: Английский

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Biotically driven vegetation mosaics in grazing ecosystems: the battle between bioturbation and biocompaction

Ecological Monographs, Год журнала: 2017, Номер 87(3), С. 363 - 378

Опубликована: Март 19, 2017

Abstract Grazing ecosystems ranging from the Arctic tundra to tropical savannas are often characterized by small‐scale mosaics of herbivore‐preferred and herbivore‐avoided patches, promoting plant biodiversity resilience. The three leading explanations for bistable patchiness in grazed (1) herbivore‐driven nutrient cycling, (2) plant‐growth–water‐infiltration feedback under aridity, (3) irreversible local herbivore‐induced abiotic stress (topsoil erosion, salinity). However, these insufficiently explain high temporal patch dynamics wide‐ranging distribution grazing across productive habitats. Here we propose a fourth possibility where alternating patches governed interplay two important biotic processes: bioturbation soil fauna that locally ameliorates conditions, tall communities, with biocompaction large herbivores impairs promotes lawn communities. We review mechanisms rapid conversions between bioturbation‐ biocompaction‐dominated provide global map this mechanism is possible. With simple model illustrate expands range conditions which can persist. conclude response systems change, as degradation or catastrophic droughts, will be contingent on correct identification dominant process drives their vegetation structural heterogeneity.

Язык: Английский

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Changes in the Shadow: The Shifting Role of Shaded Leaves in Global Carbon and Water Cycles Under Climate Change

Geophysical Research Letters, Год журнала: 2018, Номер 45(10), С. 5052 - 5061

Опубликована: Май 8, 2018

Abstract Globally shaded leaves contribute to more than a half of the total increase in gross primary production (GPP; 7.6 Pg C) for 1982–2016. During 1982–2016, fraction GPP increases by 1.1% ( p < 0.01) tropical forests and decreases 1.4% 1.8% evergreen needleleaf deciduous boreal forests, respectively, suggesting an ecological niche certain canopy structure ecosystems achieve maximum GPP. Unlike transpiration from sunlit that has turning point trend 2003, global steadily increased at rate 34 km 3 /year 0.0001) during Our study therefore suggests have increasing role buffering adverse impact climate change extremes. Further studies are still needed reduce uncertainties reported trends arisen forcing data, leaf area index, land cover products.

Язык: Английский

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Density-dependence tips the change of plant–plant interactions under environmental stress

Nature Communications, Год журнала: 2020, Номер 11(1)

Опубликована: Май 21, 2020

Facilitation studies typically compare plants under differential stress levels with and without neighbors, while the density of neighbors has rarely been addressed. However, recent empirical indicate that facilitation may be density-dependent too peak at intermediate neighbor densities. Here, we propose a conceptual model to incorporate density-dependence into theory about changes plant-plant interactions stress. To test our predictions, combine an individual-based incorporating both facilitative response effect, experiment using salt Arabidopsis thaliana. Theoretical experimental results are strikingly consistent: (1) intensity peaks density, this shifts higher densities increasing stress; (2) shift further modifies balance between competition such stress-gradient hypothesis applies only high Our suggests must considered for predicting environmental change.

Язык: Английский

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